Jennifer is right, the only way to know is by checking the map. Also, check the Stockton Record for articles regarding this issue. The city of Stockton also has a page on their website addressing the issue. Realize that the regulations are fluid so if you buy a house behind a levee even if flood insurance is not required this year or next it could change in the future. Low lying elevations and areas near rivers, creeks, streams and diversion channels are usually hardest hit.

Best to do your homework on certain areas for this one ahead of time.... try the http://www.fema.gov website